A prior art connector is shown in FIG. 4, which retains in insulated housing 5 electrical contacts 1 having aligned slots 2. Housing 5 has contact-receiving openings 6 which are arranged laterally one next to another for receiving and retaining contacts 1 therein. As one end of an insulated electrical conductor 4 is forcefully moved downwardly in a direction perpendicular to the axis of the conductor and forced into slots 2 of each contact 1, the edges of slots 2 will cut into insulation 4b and electrically engage conductor core 4a to form an electrical connection therewith. Each contact-receiving opening 6 is provided with a groove 7 for guiding conductor 4 during its movement into the housing and for retaining a portion of conductor 4 adjacent contact 1. A pair of resilient retaining arms 8 is located at the entrance of each opening of groove 7. These arms are resiliently deformed to allow a portion of conductor 4 to move into groove 7 when the electrical conductor is forced into slots 2 of contact 1 within opening 6 thereby retaining the conductor in groove 7 as shown in FIG. 5. FIG. 6 illustrates the condition of the conductor thus seated in slots 2, which shows that the slot edges of slots 2 cut into the insulation 4b of conductor 4 to form electrical connection with the conductor core 4a terminated in slots 2.
In prior art connectors described above, a gap may be easily formed between retention arms 8 and conductor 4 in retention groove 7. Then, although retention arms 8 serve to retain the electric conductor in groove 7 against an upwardly-directed force, they cannot operate to apply a retaining force on the conductor when a longitudinal external force is applied to the conductor which will affect the termination of conductor 4 in slots 2 of contact 1.
These connectors are usually soldered to a printed circuit board 9 and the like as shown in FIG. 5 by soldering legs 3 of contacts 1 extending beneath the housing 5 with solder 9b. The heat generated in such soldering operation is conducted to insulated conductor 4 thereby causing the insulation to shrink in a direction away from the termination section of contact 1. This shrinkage may cause the conductor core 4a to be exposed at the termination, which in turn becomes a further source of connection failure due to corrosion occurring between the conductor core and the contact.